Google AdSenseGuest Advertisement

From a goggle.
Based on the very old zircon rock from Australia we know that theEarth is at least 4.374 billion years old. But it could certainly be older. Scientists tend to agree that our little planet is around 4.54 billion years old—give or take a few hundred million.May 16, 2014How Do We Know the Earth Is 4.6 Billion Years Old? | Smart News ...

At least five different and independent calculation methods, all of which pretty much agree.

Click to expand...

This bears repeating.

Like with a lot of astrophysical science, no one measurement is considered certain.

What happens is, we have multiple techniques that provide ranges - they each individually put a constraint on the age - either 'no younger than' or 'no older than' - or, sometimes, both.
So, one method might constrain the Earth to be, say, no younger than 4 billion years, but could be older, whereas another method might say no older than 5 billion years, but could be younger.

Then we use other methods that further narrow it. when we get a half dozen methods that all agree, we conclude that we have a pretty good idea of the Earth's age.

But it is always changing by a little. A few million years either way, as we refine our tests.

Those constraints still apply though. The Earth's age will never be 3 billion years, or 7 billion years. We're just fine-tuning it now.

originIn a democracy you deserve the leaders you elect.Valued Senior Member

Like with a lot of astrophysical science, no one measurement is considered certain.

What happens is, we have multiple techniques that provide ranges - they each individually put a constraint on the age - either 'no younger than' or 'no older than' - or, sometimes, both.
So, one method might constrain the Earth to be, say, no younger than 4 billion years, but could be older, whereas another method might say no older than 5 billion years, but could be younger.

Then we use other methods that further narrow it. when we get a half dozen methods that all agree, we conclude that we have a pretty good idea of the Earth's age.

But it is always changing by a little. A few million years either way, as we refine our tests.

Those constraints still apply though. The Earth's age will never be 3 billion years, or 7 billion years. We're just fine-tuning it now.

Click to expand...

I think that is a nice simple overview of how the age of the earth is determined.

From a goggle.
Based on the very old zircon rock from Australia we know that theEarth is at least 4.374 billion years old. But it could certainly be older. Scientists tend to agree that our little planet is around 4.54 billion years old—give or take a few hundred million.May 16, 2014How Do We Know the Earth Is 4.6 Billion Years Old? | Smart News ...